package com.itheima.reggie.filter;


import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


/**
 * 检查用户是否已经完成登陆
 */
@Slf4j
//添加@WebFilter注解使过滤器在运行时生效。
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符（ AntPathMatcher：Spring中提供的路径匹配器 ;）
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        long id = Thread.currentThread().getId();
        //log.info("线程id为：{}",id);

        //1、获取本次请求URI
        String uri = request.getRequestURI();//   /backend/index.html

        log.info("拦截到请求：{}", uri);

        //定义不需要处理的请求路径
        String[] urls = {
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/login",
                "/user/sendMsg",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };

        //2、判断本次请求是否需要进行处理
        boolean check = check(urls, uri);
        //3、如果不需要处理则直接放行
        if(check){
            log.info("本次请求{}不需要处理:",uri);
            filterChain.doFilter(request,response);
            return;
        }
        //4-1、判断登陆状态，如果已经登陆，则直接放行
        if(request.getSession().getAttribute("employee")!=null){
            log.info("员工已经登陆，员工信息为:{}",request.getSession().getAttribute("employee"));

            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);


            filterChain.doFilter(request,response);
            return;
        }

        //4-1、判断登陆状态，如果已经登陆，则直接放行
        if(request.getSession().getAttribute("user")!=null){
            log.info("用户已经登陆，用户信息为:{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);


            filterChain.doFilter(request,response);
            return;
        }


        //5、如果未登陆则返回未登陆结果,通过输出流的方式向客户端页面响应数据
        log.info("用户未登陆");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param uri
     * @return
     */
    private boolean check(String[] urls, String uri) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, uri);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
